What a sports event contract actually settles on

Pew Research Center reported on 27 May 2026 that sports made up 80% of total trading volume on Kalshi and 39% on Polymarket since July 2024. By that measure, the contract most people hold on a US event exchange is a contract about a game, and the rule that decides it is not the one they think.

A reader who watched the game and knows who won can still be surprised by the settlement on at least five counts: which source's result is used, whether overtime was inside the contract, what happens to a game that is postponed or stopped, what happens when the player a contract is about never plays, and whether a correction published the next morning changes anything. Every one of those is written into a filed document, and the documents are specific. This page reads them. It is the sports case of who decides the outcome, which covers the general machinery — review committees, finality, appeal — and does not repeat it here. Whether a sports event contract is a swap or something a state may regulate as gaming is a separate and live legal question, set out on event contract or swap; this page takes no side on it.

How it works

A sports contract on a US venue is almost never written game by game. The exchange files a template with the CFTC under the self-certification rule, with variables in angle brackets — <team>, <football game>, <time period> — and each market you see is one listing that fills those variables in. The template carries the settlement rules; the listing carries the game, the team and, crucially, the period of play. Both halves are binding, and a reader who only sees the listing's title is missing the half that decides the edge cases.

The chain from a play on the field to a settled contract then has four links:

1. The governing body produces the official result, and for statistics the official box score or play-by-play.
2. A source on the contract's list publishes it. The list is ranked; if the first source is silent, the next one decides.
3. The exchange reads the first official final result and determines the expiration value. Trading closes; settlement follows.
4. If the game produced no usable result — postponed beyond the window, abandoned too early, a player who never played — the exchange applies a fallback written into the terms instead.

The source is a ranked list

Kalshi's football win contract, self-certified on 18 February 2026, names the Source Agencies "in hierarchical order": the governing league or association (the NFL, NCAA or UFL are the examples given), ESPN, CBS Sports, Fox Sports, NBC Sports, the Associated Press, The Wall Street Journal, and the official broadcaster of the game. Its basketball statistics contract reads the "official box score and/or play-by-play" and ranks the league, ESPN, Fox Sports and the official broadcast partner. Its soccer win contract has the longest list of the documents read for this page: the organiser's official website and communications, then Reuters, the Associated Press, Bloomberg News, ESPN, BBC Sport, The New York Times, The Athletic, The Guardian, Sky Sports and Opta (Stats Perform).

Rothera Exchange and Clearing's baseball contract, certified on 13 May 2026, uses nearly the same list as Kalshi's football one. Polymarket US's sports documentation describes a three-tier hierarchy: the governing body first, then "official competition scorecards, referee or umpire reports, press releases, and results databases maintained by the governing body," then the Associated Press, Reuters, ESPN, BBC Sport, official team and league websites and "major sports wire services or data providers."

Crypto.com | Derivatives North America (CDNA) is the exception in what its filings name. Its July 2025 certification for sports outcome contracts says the Source Agency "is set forth on the Exchange website or on the Trading System as either a news provider or market data provider", and its August 2025 statistics contract, Rule 13.64, defines it as "the final Statistic reported by the data provider as set forth on the Exchange website and/or Trading System." The filings do not name the provider. The help centre article says contracts settle "based on the result issued by the relevant news or market data provider", again without a name.

The first final result, and when it stops moving

This is where a sports contract differs most from a reader's instinct, because leagues do revise results and statistics after the final whistle, and contracts mostly ignore it.

• Kalshi, football. "The market resolves based on the first official final result reported unless the Exchange, in its sole discretion, has reason to believe that the first official final result is clearly erroneous, in which case it may defer to a corrected official final result if such a correction is made prior to Contract Expiration. Subsequent corrections or revisions after Expiration will not be considered." The terms also move expiration earlier once a winner is reported, under Kalshi Rule 7.2 — so the window in which a correction still counts can close soon after the game.
• Kalshi, basketball statistics. Stricter: "Statistics are considered final at the conclusion of <basketball game>. Corrections made afterwards will not affect the value of the Contract."
• Kalshi, soccer spreads. "The final whistle determines the official count - any subsequent reviews or appeals do not affect settlement." Goals confirmed or disallowed by VAR follow the final on-field decision.
• Kalshi, soccer win. The official result is the one the organiser confirms, including VAR decisions and a penalty kick taken after the whistle for an earlier incident. What it does not give effect to is "any change arising after the organizer … has officially confirmed or published the final result, including any change by reason of protest, appeal, administrative or disciplinary proceeding, sporting sanction, points adjustment, or forfeiture." The terms give the example directly: a team confirmed as the 2–1 winner and later stripped of the match by a disciplinary body for fielding an ineligible player still resolves Yes.
• CDNA, statistics. Rule 13.64(o): the expiration value "is final when the event(s) related to the Statistic is completed and will not be amended should the data provider amend the Statistic after the event is completed." The help centre says the same for sports contracts generally: "Statistics are considered final at the time of settlement."
• Rothera, soccer. "Any subsequent revisions to the initial release of the final result … will NOT affect or alter the settlement value of the Contract once the Expiration Value is determined by the Exchange."
• Polymarket US. The sports documentation read for this page does not say how a correction after the game is treated. It does say that if a game is replayed in its entirety "pursuant to a protest or governing body decision before the Contract's expiration date, the replay result governs." Rule 10.4 of its rulebook lets the exchange review a contract before settlement and reverse an outcome "in the case of obvious error".

The practical reading is the same everywhere it is written down: a stat the league re-credits the next morning, an appeal that overturns a result a week later, a forfeit awarded after the fact — none of it reaches a contract that has already expired.

Overtime and extra time

In American football, basketball, baseball and hockey, overtime is inside the contract by default in every set of terms read for this page. Kalshi's football terms: "Unless otherwise specified, all overtime periods are included in determining the winner." Its basketball terms define the default period as "the sum of regulation time and overtime." Rothera's baseball terms include "all extra innings or tie‑breaking procedures." Polymarket US includes "overtime, extra time, extra innings, penalty shootouts, and tiebreakers" by default for game-level contracts. The Crypto.com help centre says overtime counts for full-game football markets unless stated otherwise, extra innings count for all baseball markets, and in hockey "overtime and shootouts count", with the shootout winner credited one goal.

A football game can still end level. Kalshi's terms settle each tied team's contract at "$1/(the number of tied teams), rounded down" — 50 cents each for two teams — rather than to No.

Soccer is the exception, and the venues do not agree on how.

The last two rows are the same exchange. A knockout match that finishes 1–1 and is decided on penalties resolves No on a Kalshi "regulation time" win contract, Yes on a "full match" contract for the shootout winner, and, on a spread contract with no period specified, counts the extra-time goals but not the shootout. None of that is visible in a title that reads "Team A to win".

Postponed, suspended and abandoned games

Every venue splits this the same way — before play starts, after it starts but before it counts, and after it counts — and every venue draws the lines in different places.

Postponed before kickoff. Kalshi's football terms keep a market open if the game "is rescheduled and begins play within 48 hours of its originally scheduled date"; otherwise it resolves at the last fair market price. Its soccer win terms use the same 48 hours, measured from the original start time. Its basketball statistics and soccer spread terms allow two weeks: "If <basketball game> is delayed for two weeks or less, all markets … will remain open." Polymarket US keeps a contract open if the rescheduled game falls before the contract's expiration date, "typically two weeks from the original event date", and its Rule 10.3(b) lets the exchange adjust an expiration date for "the rescheduling or cancellation of a relevant event." Crypto.com treats an event "postponed, canceled or otherwise not completed within 48 hours of its originally scheduled start" as a Canceled Event, with 14 days for tennis.

Stopped after it starts. Here the question is whether enough of the game was played to count.

• Kalshi, football: stopped before 55 minutes of play and not resuming — last fair price, except for periods already finished, which settle on their actual result. After 55 minutes, the same, unless "the governing league declares a winner or final result", which then governs.
• Kalshi, basketball statistics: abandoned after the start and not recommencing within 24 hours — last fair price, except final-score markets once 48 minutes have been played in an NBA game or 40 in a WNBA or college game.
• Kalshi, soccer win: if 90 minutes of regular-time play "(not inclusive of stoppage time)" had been completed, the result at that point governs a regulation-time contract. A match resumed from the point of suspension within 48 hours of the original start stays live; a match replayed from zero within 48 hours is treated as the same game.
• Polymarket US: if the game reached "the official game threshold required by the governing body to declare a result", the official result at the stoppage governs; if not, and it is not completed before expiration, contracts settle at the last fair market price. For baseball, an official result declared by MLB governs "regardless of how many innings were played."
• Rothera, baseball: a game shortened but declared official settles on that result; one not completed within two days of its scheduled start settles at the last fair market price.

Forfeits are where two exchanges reached through the same app disagree. Under Kalshi's soccer win terms, a result awarded before play starts by reason of forfeit, withdrawal or walkover settles at the last fair price. Under Rothera's soccer outcome terms, a team that "forfeits <soccer match> before <soccer match> begins" resolves No, and the opposing team resolves Yes.

A player who does not play

Contracts on a single player's statistics add a question a game contract never faces: the game happened, but the player was not in it. Three venues publish an answer, and they are three different answers.

• Kalshi (basketball statistics and soccer spreads): if the player "withdraws prior to the commencement" of the game, contracts on that player resolve to the last fair price. If the player retires or is injured during the game, contracts settle on end-of-game statistics "if <entity> have played for at least one (1) second."
• Polymarket US: "If the player doesn't participate at all, the Contract settles at LFMP" — last fair market price. A player who leaves early is settled on the statistics accumulated per the official box score.
• Crypto.com splits the case in two, and the split decides the contract. In football, basketball and hockey: "If a player is declared inactive or out before the start of the event, contracts are settled as Event Canceled," but "If a player is active but does not enter the game, contracts settle out-of-the-money." In baseball, a player not in the starting lineup is an Event Canceled. In soccer, a player who never takes the field or withdraws before the match is settled as Event Cancelled. A Formula 1 driver who does not start settles out-of-the-money.

So on Crypto.com the same absence can be worth a fallback price or nothing, depending on whether the player was listed inactive before the game or dressed and sat. On Kalshi and Polymarket US the test is simply whether the player took part.

What it costs

The cost of an edge case is the fallback price, and the three fallbacks are not the same number.

• Kalshi: "the last fair price as determined by the Exchange in its sole discretion." The terms do not say how it is computed.
• Polymarket US: last fair market price, which its documentation defines as "the prevailing fair market price on the Exchange at a specified moment in time, typically the moment an official announcement is made … It is not the last traded price at market close." Trades after the announcement "are executed at the trader's own risk" and do not move the settlement. Its rulebook's separate Rule 10.5, for contracts about a person who dies or is incapacitated, uses last traded prices instead.
• Crypto.com: a volume-weighted average. On a Canceled Event, Yes holders receive "the Volume-Weighted Average Price (VWAP) prior to cancellation, calculated over the one-week period immediately preceding the determination," and No holders receive $1 minus that.
• Rothera: last fair market price under its Rule 7.2; long holders receive the number of contracts times that price and short holders $1 minus it.

A week-long average and a price at the moment of an announcement can be very far apart for the same game — the first reflects where the market sat before the news, the second where it sat when the news broke.

Combined contracts multiply the edge cases. Kalshi's multi-leg contract, certified on 2 September 2025 as "Will <outcomes> occur in <events>?", incorporates each leg's own rulebook by reference, and "'Yes' in this contract will pay out the product of the payouts for each <component>, as dictated by each corresponding <rule>, rounded down to the nearest cent." One leg settled at a fair price of 40 cents turns a winning combination into, at most, 40 cents.

And capital is locked for longer than the game. Kalshi's latest expiration is one week after the period for its football contract and fifteen days after the game for its basketball statistics and soccer win contracts, with settlement no later than the next day unless the outcome is under review. Rothera's baseball contract expires at the latest two days after the scheduled date, at 10:00 AM CT. Crypto.com's help centre says a contract is settled within 24 hours of the outcome being determined. A postponed game holds the position open for the whole window the terms allow.

Where the other venues stand

Robinhood resolves nothing itself. Its event contracts are routed to KalshiEX, ForecastEx or Rothera, and the contract settles under that exchange's terms. Robinhood said on 4 June 2026 that it was "sending a selection of World Cup and professional baseball contracts to Rothera" and would add events over time; the announcement does not say how a customer tells which exchange a given contract sits on. The forfeit difference above is the reason that matters.

ForecastEx lists no sports contracts at the time of its card's last check, although its rulebook does not bar them.

Polymarket's international platform resolves sports markets through the same UMA oracle process as everything else it lists, against the rules text of each market; no sport-wide document comparable to the filed terms above was found for it. The mechanism, and what it does with a question that has no clean answer, is on who decides the outcome.

The CFTC has proposed to weigh settlement data itself. Its notice of proposed rulemaking on prediction markets, issued on 10 June 2026 under RIN 3038-AF65, says that sports contracts settling "by reference to publicly reported, league-verified, or otherwise objectively determinable data" would be a factor weighing against a finding that they are contrary to the public interest, and preliminarily finds that contracts settling "solely by reference to" an athlete's injury, or solely to officials' judgement calls, would likely be found contrary to it. It is a proposal until a final rule is published under the same RIN; what it would change beyond settlement is on event contract or swap.

What you can do about it

Read the period before the price. On any soccer contract, find whether the listing says regulation time, full match or to advance. On a knockout match those are three different contracts, and the title can read the same for all three. On Kalshi the variable values, the contract terms and the settlement sources are published per series through the public API; reading a market's rules from the API walks through where they are.

Know which source is first on the list. Where the contract ranks the league first, the league's official box score or match report is the document, not a scoreboard in an app. Where the provider is not named — CDNA's filings leave it to the exchange website or trading system — ask the exchange which provider it is before you rely on a particular statistic.

Assume the first final result is the last one. Every venue that addresses corrections closes the window at expiration or earlier, and Kalshi moves expiration forward once a winner is reported. If you think a published result is wrong, the time to raise it with the exchange is before the contract expires; after that, the terms say it will not be considered.

For a contract on one player, find out which of three answers applies before the game. A fair price set by the exchange, a week-long average, or zero. On Crypto.com the answer turns on whether the player was declared inactive or out before the start, so the timing of the team's own announcement is part of the contract.

On Robinhood, find out which exchange the contract is on. The rules are that exchange's, and Kalshi and Rothera settle a pre-match soccer forfeit in opposite ways.

Treat a price gap between two venues on the same game as a rules question first. Overtime, the postponement window and the player-absence rule each move a fair price without anybody being wrong about the game. The general case is why the same contract costs two prices; the per-venue detail, each dated to the document it was read from, is in the prediction market venues listing.